Working machines such as, for example, self-propelled working machines are typically used for outdoor work. For example, a self-propelled working machine collects pieces of lumber, branches, leaves, building materials, wastes, etc. at a location where they are placed and carry them to, for example, a dump truck or a place where they are used or discarded.
Such a self-propelled working machine is typically formed with a frame, a drive section, a body section and a boom unit. The drive section is mounted to the frame for propelling the working machine on the ground. The body section is mounted to the frame and is positioned thereabove. The body section has a prime mover such as, for example, an engine for powering the drive section. The boom unit extends from the body section and has an attachment to make various kinds of work such as the collecting work. The boom unit is relatively long to reach a remote place. The longer the boom unit, the larger the work area.
After finishing such work, typically, a truck transports the self-propelled working machine to a storage site from the work site. Due to the length of the boom unit, however, the boom unit can project outside the body section if the boom unit is simply laid down onto the body section. Conventionally, therefore, the boom unit is detached from the body section and separately loaded to the truck. For example, JP-A-2003-165691 and JP-A-2004-99251 disclose such a type of working machines.
Because the boom unit is relatively heavy, the detaching operation (or attaching operation) made at the work site is troublesome and extremely deteriorate the work efficiency. Particularly, if the working machine is used at a mountain side which has fewer scaffolds, the detaching (or attaching) operation can be more difficult. Normally, a small working machine thus is only available at the site, and work persons are required to do hard work manually.